The Kitab at-Tasrif (Arabic: كتاب التصريف لمن عجز عن التأليف) (The Method of Medicine) was an Arabic encyclopedia on medicine and surgery, written near the year 1000 by Abu al-Qasim al-Zahrawi (Abulcasis). It is available in translation. One of Al-Zahrawi’s greatest contributions was the Kitab al-Tasrif, a 30-volume encyclopedia of medical information. The Kitab al-Tasrif took Al-Zahrawi over 50 years to complete. It contains information about a wide variety of illnesses, injuries, medical conditions, treatments, and surgical procedures. He even describes over 200 different surgical instruments. It is said that almost 90% of surgical instruments being used today were demonstrated by Abulcasis. Surgeons continued to use the information in the Kitab al-Tasrif well into the 1700s. In fact, some of Al-Zahrawi’s surgical procedures are still being used to this very day. This book was included in the course studies of some of the biggest universities in Europe till the late 1800s. With so much contribution to Surgical science, Abulcasis is called the most influential Arab Surgeon ever born.